1. Field of the Invention
The present invention relates to a mechanical device of combined internal ventilation for protective helmets. More specifically, a ventilation system that is entirely hidden on the inside of the helmet cap, and therefore does not create discontinuities on the external surface of said cap.
2. The Prior Art
As is known, protective helmets usually contain a cap, or external shell, made of rigid and resistant material. Also provided on the front, in correspondence of the eyes, is a wide opening closable by means of a visor that is liftable and made of a transparent material and, in some cases, is also removable.
The so-called integral helmets have, in the inside of the cap a safety padding made from soft material. It is also known that integral helmets, because of their particular structure involve the necessity of being internally ventilated by means of the circulation of an air flow in order to avoid the overheating of the head and/or the formation of condensate due to the perspiration of the user.
In order to provide adequate internal ventilation of the cap, various solutions have been already proposed which are usually based on the principle of capturing air from the outside through openings of various shapes and sizes. These openings are typically placed in the front part of the helmet, above the visor, causing air to circulate between the padding layers by means of canals of various conformations and positions, and then of exhausting it from the helmet back.
A type of integral helmet is also known that includes air intakes in the lower front part. The circulation of air in the inside of the padding and outlet occurs both laterally and at. the top of the cap. In this case, baffles are provided, which are suitable to create a depression capable of drawing warm air from the inside of the helmet and exhausting it towards the outside.
In practice, it has been observed that the known ventilation systems include direct air intakes through openings obtained on the front of the helmet, either by the visor or in the chin protector. These systems usually involve uncomfortable conditions of localized cooling, especially at high speeds, and an insufficient ventilation at low speeds. This is due to the different load losses undergone by the air flow in the canals, the deviation and exhaust openings.
In addition, the internal ventilation devices have the drawback of needing means to activate the opening and closing wings of air intakes. The activators are usually translatable sliders, or the like, emerging from the external surface of the caps. The present systems have drawbacks such as the poor aesthetics and the aerodynamics of the cap, as well as cumbersome cleaning of the same.